CN113143394A

CN113143394A - Patient-specific augmented glenoid system

Info

Publication number: CN113143394A
Application number: CN202110360616.XA
Authority: CN
Inventors: M·F·科瓦克斯; L·古洛塔; T·M·瓦纳斯
Original assignee: Biomet Manufacturing LLC
Current assignee: Biomet Manufacturing LLC
Priority date: 2015-04-24
Filing date: 2016-04-22
Publication date: 2021-07-23
Also published as: US10806591B2; CN108135707A; CN108135707B; JP2018516634A; AU2016250842A1; CA2983650C; JP6885878B2; CA2983650A1; US10034757B2; US20160310285A1; EP3788967A2; US20180303618A1; JP2020054840A; EP3291768A1; EP3291768B1; JP6947802B2; US20210000605A1; AU2016250842B2; EP3788967A3; WO2016172572A1

Abstract

The glenoid implant includes: a body comprising an articular surface and a scapula-engaging surface, the scapula-engaging surface comprising first and second portions that are angled with respect to one another; and a fixation feature extending from the scapula-engaging surface. The method comprises the following steps: forming a planar bone surface at the glenoid using the guide pin; forming a first hole in the glenoid located adjacent the guide pin; forming a second hole in the glenoid offset from the first hole; inserting a reinforcing reaming guide into the first and second bores; and forming an angled bone surface on the glenoid relative to the planar bone surface using the augment guide. The reaming guide comprises: a base having first and second surfaces; a bone pin extending from the first surface; an alignment pin spaced from the bone pin; and a guide pin extending from the second surface at an oblique angle relative to the bone pin.

Description

Patient-specific augmented glenoid system

The present application is a divisional application of an invention patent application having an application date of 2016, 22/04, and an application number of 201680034735.3, entitled "patient-specific augmented glenoid system".

Require priority

This patent application claims priority from U.S. provisional patent application No.62/152304 entitled "PATIENT SPECIFIC AUGMENTED GLENOID PREP (patient-specific enhanced GLENOID)" filed 24/4/2015, the entire contents of which are incorporated herein by reference.

Technical Field

This document relates generally, but not by way of limitation, to systems and methods for preparing bone for orthopaedic implants. More particularly, the present disclosure relates to, but is not limited to, preparing a bone surface to receive an orthopaedic implant having a non-symmetrical bone-engaging surface.

Background

In cases where glenoid wear is severe, it may be difficult to restore the joint to a near neutral condition using standard implants. In these cases, the surgeon must make a compromise: placing the component at a non-ideal twist angle, removing a significant amount of native bone to obtain full dorsal coverage of the glenoid base, or performing a bone graft to support the dorsal side of the glenoid implant.

Recently, glenoid implants with reinforcements have been developed as an option for cases of severe glenoid wear. For anatomical shoulder arthroplasty, the augmented glenoid implant may include various stepped or contoured bone contacting surfaces. However, many of these designs still require the removal of a significant amount of bone.

Examples of glenoid implants are described in U.S. patent publication No. 2015/0150688 to Vanasse et al, U.S. patent No.6699289 to Iannotti et al, U.S. patent No.9233003 to Roche et al, and U.S. patent No.7753959 to Berelsman et al.

Disclosure of Invention

The present inventors have recognized, among other problems, that problems to be solved may include a need to reduce the amount of bone removal when implanting a glenoid implant. Furthermore, the present inventors have recognized that another problem to be solved may include the need to simplify various bone preparation techniques when installing glenoid implants.

The present subject matter may help provide a solution to this problem, for example, in patient-specific and non-patient-specific embodiments, by providing augmentation implants having angled, and partially angled bone-contacting surfaces, as well as instruments and methods for implanting such augmentation implants.

The glenoid implant may include a body including: an articular surface configured to mate with or receive another component, the other component configured to mate with a complementary component; and a scapula-engaging surface opposite the articular surface and including first and second portions angled relative to one another; and a fixation feature extending from the scapula-engaging surface.

A method of implanting a scapula baseplate in a shoulder arthroplasty may comprise: inserting a guide pin into a glenoid of the scapula using a guide instrument; preparing a first portion of the glenoid to form a planar bone surface using the guide pin; forming a first hole in the glenoid located substantially at the guide pin; forming a second hole in the glenoid offset from the first hole; inserting a reinforcing reaming guide into the first and second bores; and preparing a second portion of the glenoid to form an angled bone surface relative to the planar bone surface using the augment reaming guide.

A reaming guide for a shoulder arthroplasty procedure may include: a base having a first surface and a second surface; a bone nail extending perpendicularly from the first surface; an alignment pin extending from the first surface and spaced apart from the bone pin; and a guide pin extending from the second surface opposite the bone pin at an angle oblique to the bone pin.

This summary is intended to provide an overview of the subject matter of the present patent application. This is not intended to provide an exclusive or exhaustive explanation of the invention. The detailed description is included to provide further information regarding the present patent application.

Drawings

Fig. 1 is a cross-sectional view of an anatomical shoulder replacement system of the prior art, including a glenoid implant for implantation in a scapula and a humeral head for implantation in a humerus.

Fig. 2 is a cross-sectional view of a prior art reverse shoulder joint replacement system including a glenosphere baseplate for implantation of a scapula and a humeral disc and humeral implant for implantation of a humerus.

Fig. 3A is a perspective view of a reinforcing base plate for a reverse shoulder implant, the reinforcing base plate having an angled bone surface with holes for receiving fixation fasteners and a glenosphere.

Fig. 3B is a perspective view of the reinforcement substrate of fig. 3A implanted in the scapula.

Fig. 4A is a perspective view of a guide pin inserted into the glenoid of the scapula using a standard glenoid guide instrument.

Fig. 4B is a perspective view of the insertion of the guide pin into the glenoid of the scapula with the patient-specific glenoid guide instrument.

Fig. 5A is a perspective view of the facereamer advanced along the guide pin of fig. 4A or 4B to partially ream the scapula hole.

Fig. 5B is an enlarged view of the partially reamed scapula of fig. 5A with the guide pin inserted.

Fig. 6A is a perspective view of an enhancement sizer advanced along the guide pin of fig. 4A or 4B to measure the size of a partially reamed scapula.

Fig. 6B is a side cross-sectional view of the augmentation sizer of fig. 6A properly seated against the properly reamed glenoid.

Fig. 7A is a perspective view of an alignment pin drill guide advanced along the guide pin of fig. 4A or 4B to drill an alignment hole in a partially reamed scapula.

Fig. 7B is an enlarged view of the partially reamed scapula of fig. 5A including an aligned hole created using the drill guide of fig. 7A.

Fig. 8A is an exploded view of the augment reaming guide, fixation fastener, and driving instrument.

Fig. 8B is a perspective view of the augment reaming guide seated against the partially reamed scapula with the drive instrument inserted into the augment reaming guide.

Fig. 8C is a side view of the reinforcement reaming guide of fig. 8A and 8B.

Fig. 9A is a perspective view of the enhanced reamer advanced along the enhanced reaming guide of fig. 8A-8C to further ream the partially reamed scapula.

Fig. 9B is an enlarged view of the fully reamed scapula of fig. 9A.

FIG. 10A is an exploded view of the alignment post of the reinforcing base plate impactor aligned with the alignment holes of the reinforcing base plate and the scapula.

FIG. 10B is a perspective view of the impact face of the enhanced substrate impactor showing alignment posts, a center post, and peripheral posts.

Fig. 11 is a perspective view of a reinforcing base plate for an anatomical shoulder implant having an angled bone surface with fixation posts.

Fig. 12 is a schematic view of a patient-specific glenoid guide engaged with the glenoid of the scapula to mount the guide pin substantially parallel to the anatomical axis.

Fig. 13 is a schematic view of the depth stop being installed around the guide pin of fig. 12.

Fig. 14 is a schematic view of the underreamer being installed around the guide pin and depth stop of fig. 13.

Fig. 15 is a schematic view of the guide pin mounting boss and post reamer being surrounded in fig. 13.

Fig. 16 is a schematic view of the peripheral post reamer guide being installed around the guide pin of fig. 13.

Fig. 17 is a schematic view of a patient-specific angled reaming guide being installed with a compression screw following the path of the guide pin of fig. 13.

Fig. 18 is a schematic drawing of the underreamer being installed around the angled underreamer guide of fig. 17.

Fig. 19 is a perspective view of a reinforcing base plate for an inverted shoulder implant having an inclined or beveled bone surface with fixation posts.

Fig. 20 is a schematic view of a patient-specific glenoid guide engaged with the glenoid of the scapula so as to mount the guide pin at an angle.

Fig. 21 is a schematic view of a depth stop surrounding the guide pin of fig. 20.

Fig. 22 is a schematic view of the reamer being advanced over the guide pin of fig. 20 to encompass the depth stop and at least partially ream the glenoid.

Fig. 23 is a schematic illustration of a patient-specific drill guide mated to the partially reamed glenoid of fig. 22 to form a central post bore with a reamer.

Fig. 24 is a schematic illustration of a patient-specific peripheral post reamer guide being advanced into the reamed central post bore of fig. 23 to form a peripheral bore with the reamer.

Fig. 25 is a schematic view of the augment base plate of fig. 19 installed over a partially reamed glenoid such that the oblique bone surfaces and respective fixation posts mate with the prepared glenoid.

The drawings are not necessarily to scale, and in the drawings, like numerals may depict like parts throughout the different views. Like numerals having different letter suffixes may represent different embodiments of similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed herein.

Detailed Description

Fig. 1 is a cross-sectional view of a prior art anatomical shoulder implant 10 including an implanted glenoid implant 12 and an implanted humeral implant 14. The glenoid implant 12 can include a glenoid 16 and the humeral implant 14 can include a humeral head 18. Glenoid implant 12 can be secured to glenoid G of scapula S using a central post 20 and peripheral posts 22. The humeral implant 14 can be secured to the humerus H using any suitable means, such as a central post 24 and

fasteners

26A and 26B. Glenoid G of scapula S may be generally reamed to provide a single surface to be engaged with bone surface 28 of glenoid implant 12. As can be seen, the glenoid implant 12 can generally have a substantially uniform thickness, and the bone surface 28 can generally comprise a single smooth surface, except for the portions associated with the central post 20 and the peripheral posts 22. These geometric features of the glenoid implant 12 may sometimes inevitably result in the removal of a certain amount of healthy bone.

Fig. 2 is a cross-sectional view of a prior art reverse shoulder implant 30 including an implanted humeral disc 32 and an implanted glenosphere baseplate 34. The humeral disc 32 can include a Polyethylene (PE) liner 36, and the glenosphere substrate 34 can include a glenosphere 38. The humeral disc 32 can be secured to the humerus H using any suitable means, such as a central post 40 and a rod 42. Glenosphere baseplate 34 can be secured to glenoid G of scapula S using spine 44 and fasteners 46A-46C. The glenosphere base plate 34 may be secured in other ways, such as by using a central post and four peripheral screws. Glenoid G of scapula S may be generally reamed to provide a single surface to be engaged with bone surface 48 of glenosphere baseplate 34. As can be seen, glenosphere baseplate 34 can generally have a substantially uniform thickness, and bone surface 48 can generally comprise a single smooth surface, except for the portions associated with central post 44 and fasteners 46A-46C. These geometric features of glenosphere baseplate 34 may sometimes inevitably result in the removal of a certain amount of healthy bone.

Fig. 3A is a perspective view of a reverse shoulder implant 50 including a reinforcing base plate 52 with an angled bone surface 54. The base plate 52 may also include a stem 56, a mating surface 57, and holes 58A-58E (56D shown in FIG. 10A) for receiving securing fasteners 60A-60E. The angled bone surface 54 may include a parallel surface 54A and an inclined surface 54B. Implant 50 may also include a glenosphere 62, and glenosphere 62 may include a stem 64. The parallel surface 54A may be parallel to the mating surface 57 and the distal surface 66 of the rod 64. In various embodiments, the substrate 52 may be made of a porous material such as highly porous metal, Trabecular

Or tantalum.

Fig. 3B is a perspective view of the reinforcement substrate 52 of fig. 3A implanted on the scapula S. Glenoid G of scapula S can be prepared to mate with parallel surface 54A and oblique surface 54B, e.g., by reaming of glenoid G to form an obliquely oriented planar bone surface. Inclined surface 54B can be located at any orientation of glenoid G. For example, the inclined surface 54B can be located superior, inferior, posterior, or anterior on the glenoid G, or in any intermediate orientation. The methods, instruments, and tools described herein, with particular reference to fig. 4A-10B, facilitate implantation of the reinforcing base plate 52 onto the scapula S in a manner that minimizes the amount of bone removal, and subsequent alignment of the reinforcing base plate such that the

surfaces

54A and 54B mate flush with the prepared surface of the glenoid G.

Fig. 4A is a perspective view of standard (i.e., non-patient specific) glenoid guide instrument 100 inserting guide pin 102 into glenoid G of scapula S. Instrument 100 may include a pin placement guide 104 and a glenoid guide handle 106.

An appropriate pin placement guide 104 may be selected based on the degree of glenoid wear. For example, the angled surface 54B of the reinforcing substrate 52 (fig. 3A) may be angled at an angle of 10 °, 20 °, or 30 ° with respect to the parallel surface 54A. Thus, pin placement guide 104 can be manufactured such that for a 10 °, 20 °, or 30 ° baseplate, guide pin 102 is substantially aligned with the central axis of the vault of glenoid G. However, a 10 degree downward tilt may be established in the pin placement guide 104. Selecting an appropriate pin placement guide 104 to align guide pin 102 in a desired version and inclination, guide pin 102 can be a Steinman pin. Glenoid guide handle 106 may be connected to a suitable augment pin placement guide 104(10 °, 20 °, or 30 °). In one embodiment, a 3.2mm steinmann pin is used as guide pin 102 and inserted into glenoid G at a desired angle and position, ensuring that pin 102 engages or perforates the medial cortical wall. A fully tightened guide pin is required to ensure that the subsequent reamer used has a stable cannula over which to ream.

When guide pin 102 is properly placed within guide 104, guide pin 102 may be flush with lower groove 107. Pin placement guide 104 can be centered on the lower portion of glenoid G. However, in cases of glenoid deformity and poor bone quality, guide pin 102 can be placed into the most probable bone.

Fig. 4B is a perspective view of patient-specific glenoid guide instrument 108 inserting guide pin 102 into glenoid G of scapula S. Patient-specific glenoid guide instrument 108 may include a base 110, an anatomical guide sleeve 112, and an inverse guide sleeve 114. The base 110 may include a patient-specific bone surface 116. At least a portion of the scapula-engaging bone surface 116 is configured to mirror and conform to the surface of the scapula S of a particular patient based on a three-dimensional (3D) model of the scapula S. In one embodiment, the patient-specific glenoid guide instrument 108 may include a Signature guide tool commercially available from Zimmer Biomet. One or more examples of Signature guide tools are described in U.S. publication No.2013/0110116 to Kehres et al, which is incorporated herein by reference in its entirety for all purposes.

Fig. 5A is a perspective view of the facereamer 118 being advanced along the guide pin 102 of fig. 4A or 4B to partially ream glenoid G of the scapula S. The face reamer 118 includes a hollow shaft 120 and a reamer head 122.

First, a non-defective half or portion of the natural surface of glenoid G can be prepared before preparing the defective or damaged half or portion of the natural surface of glenoid G. Hollow shaft 120 of face reamer 118 may be positioned over guide pin 102 and rotated to remove bone from glenoid G. In one embodiment, the bone may be reamed over at least 50% of the face of glenoid G. Due to the 10 degree downtilt of guide pin 102, lower ridge R may be clearly distinguished from bone prepared on the opposite side of glenoid wear.

Fig. 5B is an enlarged view of the partially reamed scapula S of fig. 5A with the guide pin 102 inserted therein. After the face reamer 118 is removed, guide pin 102 remains seated within glenoid G. The face reamer 118 may create a central bore 124 and a first reaming surface 126. Central bore 124 may be centered about guide pin 102, and first counterbore surface 126 may include an edge E that extends through central bore 124 at the height of guide pin 102.

Fig. 6A is a perspective view of the enhanced sizer (sizer)128 being advanced along the guide pin 102 of fig. 4A or 4B to measure the size of the partially reamed scapula S. Fig. 6B is a side cross-sectional view of the augmentation sizer 128 of fig. 6A properly seated in the properly reamed glenoid G. The enhancement sizer 128 can include a shaft 130, fingers 132, and base 134, and can have different sizes (10 °, 20 °, and/or 30 °) for different sizes of substrate 52.

It is desirable that glenoid G be reamed by at least fifty percent to ensure that glenoid G is prepared to fully support parallel surface 54A of augment base plate 52. Reaming beyond fifty percent may remove additional bone not necessary for enhanced preparation. As discussed below, in one implementation, using the enhancement sizer 128 prior to reaming, a line (which may coincide with edge E) may be drawn at fifty percent of the line on the face of glenoid G, such as with a blue marker or an electrocautery, reaming until the line disappears to ensure that glenoid G is reamed to the desired level of accuracy.

The enhancement sizer 128 can be used to measure and ensure that at least fifty percent of the face of glenoid G has been reamed. After fifty percent of the face of glenoid G is reamed, the central channel of shaft 130 can be slid onto guide pin 102 until finger 132 engages partially reamed scapula S.

After the glenoid surface has been reamed by at least 50%, different sizes of the enhancement sizers 128(10 °, 20 °, and/or 30 °) may be used to determine which size enhances the substrate 52. First, a 10 ° augmentation sizer can be placed over fifty percent of the reamed glenoid G. First, it can be assessed whether the 10 finger 132 contacts an un-reamed (defective) portion of the face of glenoid G or is protruding. If the 10 ° enhancement sizer finger 132 protrudes off the defect surface, the glenoid G can be re-evaluated with a 20 ° enhancement sizer. This is the size of the enhanced substrate 52 that may or should be selected if the 10 enhanced sizer finger 132 contacts a defect, but does not protrude out of the face of the fifty percent reamed surface. This algorithm may continue until an optimal reinforcement is found. There may be instances where the defect lies between the dimensions and the surgeon may decide at his discretion, either to seek a higher reinforcement to ream the defect side; or seek shorter reinforcements to ream the high side of glenoid G. Once fifty percent of the face of glenoid G is reamed, the face reamer 118 may be removed from guide pin 102.

As described above, the enhancement sizer 128 may also be used to determine which size (10, 20, or 30) of the reinforcement substrate 52 should be used prior to reaming the scapula. The enhancement classifier 128 may have three sizes (10 °, 20 °, or 30 °) to correspond to different sizes of the enhancement substrate 52. An augmentation sizer 128 may be positioned on guide pin 102 to engage a face of glenoid G. The reinforcement sizer 128 can be dialed (e.g., rotated on the guide pin 102) to position the finger 132 in the appropriate direction to allow the largest defect to be removed and the reinforcement base 52 will be in the desired orientation. A correctly sized reinforcing sizer will engage both finger 132 and base 134 with glenoid G. As noted above, a fifty percent line on the face of glenoid G can be marked using an electrocautery or surgical marker, as this will be used in a subsequent step to determine the sufficient reaming depth just described.

Fig. 7A is a perspective view of alignment pin drill guide 136 advanced along guide pin 102 of fig. 4A or 4B to drill an alignment hole in a partially reamed scapula using drill bit 138. Alignment pin drill guide 136 may include a handle shaft 140, a base plate 142, a semi-circular etch 144, windows 146, and guide holes 148. Fig. 7B is an enlarged view of the partially reamed scapula S of fig. 5A including the alignment hole 150 made using the drill guide 136 of fig. 7A.

The base plate 142 can be positioned over the glenoid G with the semicircular etchings 144 in the precise locations where augmentation is desired. In one embodiment, at least a portion of the scapula-engaging surface of the base plate 142 may be configured to mirror and conform to the surface of the scapula S of a particular patient based on a three-dimensional (3D) model of the scapula S. Each window 146 may be referenced and centered on an edge E of the fifty percent reamed glenoid. Once properly oriented, drill bit 138 may be inserted into guide hole 148 in base plate 142, and glenoid G may be drilled to form a hole for receiving an alignment finger of an inserter (discussed below). In one embodiment, the guide bore 148 and drill bit 138 may be sized to produce a 2.7mm bore. The drill bit 138 may be advanced until the drilling depth is reached by the shoulder on the drill bit 138 being lowered onto the glenosphere substrate 142. In other embodiments, an etch may be provided on the drill bit 138 to indicate a desired drilling depth. Drilling a 2.7mm alignment hole may help facilitate enhanced orientation of the substrate 52 during insertion. Drill guide 136 can then be removed from guide pin 102 and guide pin 102 can be removed from glenoid G.

Fig. 8A is an exploded view of augment reaming guide 152, fixation fastener 154, and drive instrument 156. Fig. 8B is a perspective view of the augment reaming guide 152 seated on the partially reamed scapula S and with the drive instrument 156 inserted into the augment reaming guide 152. Fig. 8C is a side view of reinforcement reaming guide 152. reinforcement reaming guide 152 may include bone pegs 158, guide pegs 160, base 162, and alignment post 164. Glenoid G can include an alignment hole 150 created by drill bit 138 in a previous step.

Bone screw 158 may extend substantially perpendicularly from a bottom surface of base 162, and guide screw 160 may extend at an oblique angle to bone screw 158. Substantially perpendicular may include the central axis of bone screw 158 being disposed at 90 degrees relative to the bottom surface of base 162 and the central axis being within 5 degrees of perpendicular. The substantially vertical orientation of bone pins 158 may help to enhance the ease of insertion of reaming guide 152 into central bore 124.

Guide pin 102 may be removed. An appropriately sized (10 °, 20 °, or 30 °) enhanced reaming guide 152 can be placed over the prepared glenoid G, with care being taken to align the alignment holes 150 with the alignment posts 164 on the reaming guide 152. Next, bone peg 160 may be inserted into central bore 124 in glenoid G and fixation fastener 154 may be inserted into guide peg 160 until it is fully seated within augmentation reaming guide 152. The securing fastener 154 may be inserted under manual force using a hex driver. When fully seated, an etched line 166 on the drive instrument 156 may be aligned with an etched line 168 on the reamer guide 152. The fixation fasteners 154 may be designed at the same pitch as the fixation fasteners 60E (fig. 3A) to help ensure that each thread of the fixation fasteners 60E will engage undisturbed bone. Securing fasteners 154 may provide for securing of reaming guide 152 during reaming of enhanced base plate 52.

Fig. 9A is a perspective view of an augment reamer 170 being advanced along the augment reaming guide 152 (shown in phantom) of fig. 8A-8C to further ream the partially reamed scapula S. Fig. 9B is an enlarged view of the fully reamed scapula S of fig. 9A including central bore 124, first reaming surface 126, alignment bore 150 and second reaming surface 172.

An appropriately sized (10 °, 20 °, or 30 °) enhanced reamer 170 may be placed over the guide pins 160 of the enhanced reamer guide 152. Reamer 170 may include a recess 173 extending into head 174 of shaft 176. In particular, a portion of the outer periphery of the shaft 176 may be cut away at the end of the shaft 176 that engages the head 174, and the head 174 may include a similarly positioned notch that extends into the outer periphery of the head 174 at the same circumferential location as the cut away portion of the shaft 176. The notch in the head 174 may extend to the center of the head 174 such that the head 174 has a U-shape. So configured, the reamer 170 may slide through the guide pin 160 without the axes of the shaft 176 and the guide pin 160 being coaxial. Thus, reamer 170 may be advanced perpendicular to the face of glenoid G. Thus, the reamer 170 may more directly access the incision of the patient and avoid surrounding tissue.

Reamer 170 may be fully captured on reamer guide nail 160 prior to beginning reaming, such as by having reamer head 174 contact glenoid G. The reamer shaft 176 can be rotated to remove bone. If desired, the glenoid osteophyte can be removed to allow for proper placement of the reamer 170. Reaming may continue to advance the reamer head 174 until the shoulder within the reamer shaft 176 is lowered to rest against the guide pin 160 and an appropriate amount of bone has been prepared to accept the selected size of the augment base plate 52. Reaming guide 152 may be designed to allow for the minimum amount of bone reaming required to seat reinforcing base plate 52. Next, securing fasteners 154 (fig. 8A) may be removed and the reinforcement reaming guide 152 may also be removed. Subsequently, glenoid G can include a second counterbore surface 172 opposite first counterbore surface 126. First counterbore surface 126 and second counterbore surface 172 may abut at edge E. Thus, in one embodiment, glenoid G can now accept augment baseplate 52. In particular, parallel surface 54A may abut first counterbore surface 126 and inclined surface 54B may abut second counterbore surface 172.

FIG. 10A is an exploded view of a reinforced substrate impactor 190 and a reinforced substrate 52. The reinforcing substrate impactor 190 may include alignment posts 192, and the alignment posts 192 may be used to align the reinforcing substrate 52 with the alignment holes 150. FIG. 10B is a perspective view of the impact face 194 of the enhanced substrate impactor 190, the impact face 194 showing the alignment post 192, the central post 194 and the peripheral post 196.

The strengthening substrate 52 may be placed on the impact surface 194 of the substrate impactor 190. For example, the central post 194 may be inserted into the hole 58E of the base plate 52, while the peripheral posts 196 are inserted into the holes 58A. Alignment post 192 may extend through aperture 58C for insertion into alignment aperture 150. In addition, by aligning the reinforced portion of the substrate 52 (e.g., the angled surface 54B) with a corresponding "reinforced" label on the inserter 190, the proper orientation of the impactor 190 may be determined. When alignment post 192 is in the correct orientation, a semi-circular etched portion 198 on interposer 190 may be aligned with second counterbore surface 172.

Once aligned, augment base plate 52 may be impacted into glenoid G and augment base plate impactor 190 removed. The parallel and

inclined surfaces

54A, 54B of augment base 52 may or should be seated entirely on first and second counterbore surfaces 126, 172, respectively, on glenoid G. Fasteners 60A-60E may be used to secure base plate 52 to scapula S, and glenoid 62 may be attached to base plate 52 by a rod 64.

Visual confirmation can be obtained by examining the clearance between the reamed surface of glenoid G and base plate 52 at holes 58A-58D. A small nerve hook may be used to help confirm complete seating of the baseplate 52. Due to the 10 degree downtilt of the over orientation for substrate preparation, the substrate 52 may be partially or completely sunk downwards. If cannulation is desired, the guide pin 102 may be reinserted prior to impacting the base plate 52.

Fig. 11 is a perspective view of a reinforcing base 200 for an anatomical shoulder implant having an angled bone surface 202 with fixation posts 204A-204C. The base plate 200 can also include an articular surface 206, which articular surface 206 can be configured to directly engage a humeral head. The angled bone surface 202 may include serrations or corrugations 208 that may be used to engage bone and promote bone growth. The angled bone surface 202 may include a parallel surface 210A that may be parallel to the glenoid surface 206 and an inclined surface 210B that may be at an oblique angle relative to the parallel surface 210A.

Glenoid G of scapula S can be prepared to mate with parallel surface 210A and oblique surface 210B, for example, by reaming of glenoid G to form an obliquely oriented planar bone surface. The inclined surface 210B can be in different orientations on the glenoid G depending on the particular implant and the particular patient. The methods, instruments and tools described herein, particularly with reference to fig. 12-18, facilitate implantation of the augment base 200 onto the scapula S with minimal bone removal, and subsequent alignment of the augment base such that surfaces 210A and 210B are flush with the prepared surface of glenoid G.

Fig. 12 is a schematic view of patient-specific glenoid guide 212 engaged with glenoid G of the scapula to mount guide pin 214 substantially parallel to a central axis of a dome of glenoid G. In the depicted embodiment, glenoid G is classified as a Walch B2 glenoid, such as a reverse glenoid with trailing edge wear or a glenoid with a biconcave wear pattern of an angle alpha. Patient-specific glenoid guide 212 can be placed on a face of glenoid G. Guide pin 214 can be inserted into the glenoid vault of glenoid G through glenoid guide 212.

Fig. 13 is a schematic view of the depth stop 216 mounted around the guide pin 214 of fig. 12. In one embodiment, depth stop 216 may be patient-specific, wherein the length of depth stop 216 may be sized to allow a reamer to ream a glenoid to a depth based on a bone defect of a particular patient. The depth stop 216 may include a central bore 218 that receives the guide pin 214. The outer diameter of the depth stop 216 may be sized to receive the socket of a corresponding reamer.

Fig. 14 is a schematic view of reamer 220 mounted about guide pin 214 and depth stop 216 of fig. 13. Reamer 220 may be a standard face reamer including a socket 222 for receiving depth stop 216. Reamer 220 may be advanced until end wall 224 of socket 222 engages the proximal surface of depth stop 216. Reamer 220 may form a first prepared surface 225 on glenoid G.

Fig. 15 is a schematic view of the boss and post reamer 226 installed around the guide pin 214 of fig. 13. Post reamer 226 may include a central portion 228, and central portion 228 may be configured as a reamer, drill, or rasp to remove bone from glenoid G. In particular, the central portion 228 may be stepped to provide holes 229 having various diameters within the scapula S. In particular, central portion 228 may be stepped to provide a progressively smaller diameter hole segment within scapula S as hole 229 is deeper into the bone. The central portion 228 may be shaped to match the shape of the fixing posts 204A of the strengthening substrate 200.

Fig. 16 is a schematic view of the peripheral post guide 230 mounted around the guide pin 214 of fig. 13. Post guide 230 includes

sockets

232A and 232B for receiving a reamer or reamer 234 and a socket 236 for receiving guide pin 214.

Sockets

232A and 232B are positioned relative to guide pin 214 to place

bores

238A and 238B relative to bore 229 in positions corresponding to posts 204A-204C on base 200. Thus, after post reamer 226 is removed from guide pin 214, socket 236 of peripheral post guide 230 may be slid around guide pin 214 and reamer 234 may be used to make

bores

238A and

238B using sockets

232A and 232B, respectively. The reamer 234 may include stops 240 to ensure that the

holes

238A and 238B are reamed to the depth of the

posts

204B and 204C.

Apertures

238A and 238B may be shaped to match the shape of

fixation posts

204B and 204C, respectively.

Fig. 17 is an illustration of a patient-specific angled reaming guide 242 with a compression screw 244 installed, the compression screw 244 following the path of the guide pin of fig. 13. Guide pin 214 may be removed and angled counterbore guide 242 may be inserted into bore 229. A compression screw 244 may be inserted into reaming guide 242 and threaded into scapula S along the path of guide pin 214 to stabilize reaming guide 242 for reaming. Angled reamer guide 242 may be configured similarly to reamer guide 152 of fig. 8A-8C. Reaming guide 242 may include a bone post 246, bone post 246 being shaped to at least partially fill hole 229 and including a central bore for receiving compression screw 244. The guide post 248 may extend from the bone post 246 at an angle a, which may correspond to the angle between the

surfaces

210A and 210B of the reinforcing substrate 200. Alignment post 249 may be coupled to reaming guide 242 to orient guide post 248 in the proper direction. Alignment post 249 may have the shape of 204C and bone post 246 may have the shape of post 204A.

Fig. 18 is a schematic of reamer 250 installed around guide post 248 of angled reaming guide 242 of fig. 17. Reamer head 252 includes a socket 254 for receiving guide post 248. Using the shaft 256, the reamer head 252 can be rotated to form a second prepared surface 260 on the glenoid G. Guide post 248 may act as a depth stop to limit the advancement of reamer 250. Reamer 250 thereby creates second prepared surface 260 at an angle α relative to first prepared surface 225 such that

prepared surfaces

225 and 260 mate with

surfaces

210A and 210B, respectively, of substrate 200.

Fig. 19 is a perspective view of augmented glenoid implant 300 with angled bone surface 302. Glenoid implant 300 may also include surface 304, central post 308, and

peripheral posts

310A and 310B. The angled bone surface 302 may be formed with a first thickness t1 at a first end of the surface 304 and a second thickness t2 at a second end of the surface 304.

Glenoid G of scapula S can be prepared for mating with oblique bone surface 302, for example, by partially reaming glenoid G at an angle to remove damaged bone. The inclined bone surface 302 of augment base plate 300 can then partially fit flush with the surface of glenoid G that is reamed at an angle and partially fit flush with the natural angled, non-reamed surface of glenoid G. Alternatively, substantially all of glenoid G can be reamed at a desired angle to mate with oblique bone surface 302. The methods, instruments and tools described herein, particularly with reference to fig. 20-25, facilitate implantation of the augment base plate 300 onto the scapula S with a minimized amount of bone removal, and subsequent alignment of the augment base plate 300 such that the oblique bone surface 302 is flush with the prepared surface of glenoid G.

Fig. 20 is a schematic view of patient-specific glenoid guide 312 engaging glenoid G of scapula S to mount guide pin 314 at angle β. In the depicted example, glenoid G is classified as a Walch B1 glenoid, such as a glenoid with a narrow posterior joint space, subchondral sclerosis, and osteophytes, or a glenoid with an oblique wear pattern of beta angles. Patient-specific glenoid guide 312 is placed on the face of glenoid G. Guide pin 314 is inserted into the glenoid vault of glenoid G through glenoid guide 312. Glenoid guide 312 mates with glenoid G to align guide pin 314 at an angle β, which may be the pathological angle of glenoid G. Angle β may be predetermined from the surgical plan to allow the reamer to engage the high side of glenoid G with bone damage.

Fig. 21 is a schematic view of the depth stop 316 surrounding the guide pin 314 of fig. 20. In one embodiment, the depth stops 316 may be patient-specific, one depth stop 316 length may be sized to allow the reamer to ream to a depth that will glenoid based on a particular patient's bone defect. The depth stop 316 may include a central aperture 318 to receive the guide pin 314. The outer diameter of the depth stop 316 may be sized to receive a socket of a corresponding reamer.

Fig. 22 is a schematic view of reamer 320 being advanced onto guide pin 314 of fig. 20 to surround depth stop 316 and at least partially surround glenoid G. Reamer 320 may be a standard face reamer including a socket 322 for receiving depth stop 316. Reamer 320 may be advanced until end wall 324 of socket 322 engages the proximal surface of depth stop 316. Reamer 320 may form a prepared surface 326 on glenoid G. The high side of glenoid G can be reamed to remove damaged bone in glenoid G.

Fig. 23 is a schematic illustration of a patient-specific drill guide 328 that mates with the partially reamed glenoid G of fig. 22 to form a central post bore 330 with a drill or reamer 332. The drill guide 328 may include: a base 334, which may be patient-specific to match the partially reamed glenoid G, and a cup 336, which may be shaped to receive the reamer 332 and positioned to align with the central post bore 330 in the scapula S. The base 334 is shaped to align the central post aperture 330 along the anatomical axis of the scapula S, while taking into account the fact that the base 334 may be oblique and not perpendicular to the anatomical axis. Base 334 can be registered on the periphery of glenoid G and a portion of the reamed surface of glenoid G. The drill guide 328 may also include a handle shaft 338, and the handle shaft 338 may allow the surgeon to position and stabilize the base 334 to perform reaming. Reamer 332 may be a standard boss reamer.

Fig. 24 is a schematic illustration of a patient-specific peripheral column reamer guide 340 being advanced into the reaming central column bore 330 of fig. 23 to form

peripheral bores

342A and 342B in conjunction with a reamer or reamer 344. Reamer guide 340 may include a center pin 346, where center pin 346 may be shaped to mate with center post aperture 330 to align peripheral apertures 348A and 348B with respect to glenoid G. Reamer 344 may be a standard reamer. Alternatively, a drilling rig may be used. Patient-specific peripheral post reamer guide 340 can allow for reaming of

peripheral holes

342A and 342B without the need to insert additional guide pins into glenoid G.

Fig. 25 is a schematic view of augment base plate 300 of fig. 19, with augment base plate 300 mounted to partially reamed glenoid G such that inclined bone surface 302 and

fixation posts

308, 310A and 310B mate with prepared glenoid G. Preparation of glenoid G can be performed with a patient-specific glenoid trial (not shown) with full augmentation prior to implantation of augmentation substrate 300. After the reaming of glenoid G is confirmed,

posts

308, 310A, and 310B of augment base plate 300 may be inserted into

holes

330, 342A, and 342B, respectively, of scapula S. Standard impactors may be used to insert the reinforcing base plate 300 and bone cement may also be used in the

holes

330, 342A and 342B. In one example, augment base plate 300 will begin on the anterior side of glenoid G and be angled or sloped relative to the posterior side, as opposed to the process described with reference to fig. 11-18, where the angle or slope begins from the midline of the glenoid G.

The methods, implants and tools described herein are advantageous over previous systems. For example, the patient-specific augmented reamer guide may allow for precise reaming of the glenoid with a minimal amount of bone removal, and may allow for precise fitting with a patient-specific implant. The patient-specific guide device can allow placement of a guide Pin, such as Steinmann Pin, at the angle of the pathological glenoid for face reaming, or along the main axis of the glenoid vault. The patient-specific guide may allow reaming of the glenoid boss (e.g., with a standard reamer) and may be manufactured without the need to place a second nail in the glenoid. Patient-specific augmentation implants may be made for various types of glenoid defects, such as B1, B2, or other glenoid classifications (anatomical or reverse).

Various comments and examples

Example 1 can include or use a subject such as a glenoid implant, including: a body, which may include: an articular surface configured to mate with or receive another component, the other component configured to mate with a complementary component; and a scapula-engaging surface opposite the articular surface, the scapula-engaging surface including a first portion and a second portion angled with respect to each other; and a fixation feature extending from the scapula-engaging surface.

Example 2 can include or can optionally be combined with the subject matter of example 1 to optionally include a body and a securing feature that can be made of a porous metal material.

Example 3 can include, or can optionally be combined with, the subject matter of one or any combination of examples 1 or 2 to optionally include: a body including a sidewall having a first thickness at the first portion of the scapula-engaging surface and a second thickness at the second portion of the scapula-engaging surface, the second thickness may be greater than the first thickness.

Example 4 can include or can optionally be combined with the subject matter of one or any combination of examples 1-3 to optionally include: an edge between the first portion and the second portion extending through a midline between the first portion and the second portion of the scapula-engaging surface.

Example 5 can include, or can optionally be combined with the subject matter of one or any combination of examples 1-4, to optionally include a first portion and a second portion that can both be planar.

Example 6 can include or can optionally be combined with the subject matter of one or any combination of examples 1-5 to optionally include: first and second portions, the first and second portions being angled relative to each other at an angle in a range of about 10 degrees to about 30 degrees.

Example 7 can include or can optionally be combined with the subject matter of one or any combination of examples 1-6 to optionally include a securing feature that includes a central boss for receiving a securing fastener.

Example 8 can include, or can optionally be combined with the subject matter of one or any combination of examples 1-7 to optionally include: including a plurality of post securement features.

Example 9 can include, or can optionally be combined with the subject matter of one or any combination of examples 1-8, to optionally include: a corrugated scapula-engaging surface may be included.

Example 10 may include or use subject matter such as a method for implanting a scapula baseplate in a shoulder arthroplasty, the method may include: inserting a guide pin into a glenoid of the scapula using a guide instrument; preparing a first portion of the glenoid to form a planar bone surface using the guide pin; forming a first hole in the glenoid located substantially at the guide pin; forming a second hole in the glenoid offset from the first hole; inserting a reinforcing reaming guide into the first and second bores; and preparing a second portion of the glenoid to form an angled bone surface relative to the planar bone surface using the augment reaming guide.

Example 11 can include, or can optionally be combined with, the subject matter of example 10 to optionally include: forming the first aperture in the glenoid, comprising: positioning a reamer over the guide pin to ream the first bore while preparing the first portion of the glenoid; and forming the second aperture in the glenoid, including: positioning a drill guide on the guide pin after removing the reamer and drilling the second hole.

Example 12 may include or may optionally be combined with the subject matter of one or any combination of examples 10 or 11 to optionally include: reaming the first bore by positioning a boss and a post reamer over the guide pin after preparing the first portion of the glenoid; and positioning a drill guide on the guide pin after removing the reamer and drilling the second hole.

Example 13 can include, or can optionally be combined with the subject matter of one or any combination of examples 10-12, to optionally include: a guidance instrument that may be patient specific to match the glenoid.

Example 14 can include or can optionally be combined with the subject matter of one or any combination of examples 10-13 to optionally include: a guide instrument that positions the guide pin substantially parallel to a principal axis of a dome of the glenoid, the planar bone surface being substantially perpendicular to the principal axis, and the angled bone surface being angled relative to the planar bone surface at an angle in a range of about 10 degrees to about 30 degrees.

Example 15 can include, or can optionally be combined with the subject matter of one or any combination of examples 10-14, to optionally include: preparing a first portion of the glenoid to form a planar bone surface by at least partially reaming the glenoid to approximately fifty percent of a surface area of the glenoid.

Example 16 can include, or can optionally be combined with the subject matter of one or any combination of examples 10-15, to optionally include: the first portion of the glenoid is prepared to form a planar bone surface by inserting the post of the augment reaming guide into the recess in the reamer head and shaft of the reamer.

Example 17 can include, or can optionally be combined with the subject matter of one or any combination of examples 10-16, to optionally include: positioning a depth stop over the guide pin to limit a depth to which the glenoid can be reamed.

Example 18 may include or use a subject matter, such as a reaming guide for shoulder arthroplasty, comprising: a base having a first surface and a second surface; a bone nail extending substantially perpendicularly from the first surface; an alignment pin extending from the first surface spaced apart from a bone pin; and a guide pin extending from the second surface at an oblique angle to the bone pin opposite the bone pin.

Example 19 can include, or can optionally be combined with the subject matter of example 18, to optionally include a guide pin including a hole extending into the bone pin.

Example 20 can include, or can optionally be combined with, the subject matter of one or any combination of examples 18 or 19 to optionally include: a second surface angled relative to the first surface.

Each of these non-limiting examples may exist independently or may be variously arranged or combined with one or more other examples.

The foregoing detailed description includes references to the accompanying drawings, which form a part hereof. The drawings show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are also referred to herein as "examples". Such examples may include elements other than those illustrated or described. However, the inventors also contemplate examples in which only those elements shown or described are provided. Moreover, the inventors also contemplate the use of any combination or substitution of those elements (or one or more aspects thereof) shown or described with respect to a particular example (or one or more aspects thereof) shown or described herein or with respect to other examples (or one or more aspects thereof).

If usage between this document and any document incorporated by reference is inconsistent, then usage in this document controls.

In this document, the terms "a" or "an" are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of "at least one" or "one or more. Herein, unless specifically indicated, the term "or" is used to refer to a non-exclusive representation or such that "a or B" includes "a but not B", "B but not a" and "a and B". In this document, the terms "including" and "in which" are used as the plain-english equivalents of the respective terms "comprising" and "wherein". Furthermore, in the following claims, the terms "comprises" and "comprising" are open-ended, that is, a system, apparatus, article, composition, formulation, or process that comprises elements other than those listed after such term in a claim is still considered to be within the scope of that claim. Furthermore, in the following claims, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.

The above description is intended to be illustrative and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments may be used by those of ordinary skill in the art upon reading the above description. The abstract is provided to comply with 37c.f.r. § 1.72(b), to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Moreover, in the foregoing detailed description, various features may be grouped together to simplify the present disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the detailed description as examples or embodiments, with each claim standing on its own as a separate embodiment, and it is contemplated that such embodiments may be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

1. A reaming guide for shoulder arthroplasty, the reaming guide comprising:

a base having a first surface and a second surface;

a bone nail extending substantially perpendicularly from the first surface;

an alignment pin extending from the first surface in spaced relation to the bone pin; and

a guide pin extending from the second surface opposite the bone pin at an oblique angle thereto.

2. The reaming guide of claim 1, wherein the second surface is angled relative to the first surface.

3. The reaming guide of claim 2, wherein the second surface is angled relative to the first surface to define the oblique angle.

4. The reaming guide of claim 1, wherein the oblique angle comprises ten degrees, twenty degrees, or thirty degrees.

5. The reaming guide of claim 1, wherein the guide pin includes a hole extending into the bone pin.

6. The reaming guide of claim 5, wherein the guide peg includes a first indicator line adjacent the hole.

7. The reaming guide of claim 6, further comprising:

a fastener for insertion into the aperture; and

a fastener-driving instrument configured to guide a fastener into the hole, the fastener-driving instrument including a second indicator line configured to align with the first indicator line when the fastener is properly seated in the reaming guide.

8. The reaming guide of claim 5, wherein the hole comprises an opening in the guide pin, the opening allowing the hole to extend through the bone pin.

9. The reaming guide of claim 1, wherein the bone nail extends within five degrees of perpendicular from the first surface.

10. The reaming guide of claim 1, further comprising: a reamer configured to receive the guide pin and ream to flush with the second surface.

11. The reaming guide of claim 10, wherein the reamer includes a recess configured to allow the reamer to fit over the guide pin while the shaft of the reamer is not coaxial with the guide pin.

12. The reaming guide of claim 1, further comprising: a glenoid implant having a scapula-engaging surface with first and second portions angled relative to each other at an angle equal to the angle of inclination.

13. A system for performing shoulder arthroplasty, the system comprising:

a reaming guide, comprising:

a base extending along a first axis, the base comprising:

a first surface disposed perpendicular to the first axis; and

a second surface opposite the first surface and disposed at an oblique angle to the first axis;

a bone nail extending substantially perpendicularly from the first surface;

a guide pin extending substantially perpendicularly from the second surface; and

a fastener hole extending into the bone nail; and

a reamer, comprising:

a hollow shaft extending along a second axis,

an reamer head disposed at an end of the hollow shaft, the reamer head configured to cut bone substantially perpendicular to the second axis; and

a recess extending into the hollow shaft proximate the reamer head to receive the guide pin.

14. The system of claim 13, wherein the fastener hole comprises an opening that allows the fastener hole to extend through the bone nail.

15. The system of claim 13, wherein the reaming guide further comprises an alignment pin extending from the second surface opposite the bone pin at an oblique angle relative to the bone pin.

16. The system of claim 13, further comprising: a glenoid implant including a scapula-engaging surface having first and second portions angled relative to each other at an angle equal to the inclination angle.

17. The system of claim 13, further comprising: a fastener-driving instrument configured to guide a fastener into the hole.

18. The system of claim 17, wherein the reaming guide includes a first indicator marking that intersects the fastener bore.

19. The system of claim 18, wherein the fastener-driving instrument includes a second indicator configured to align with the first indicator when the fastener is properly seated in the fastener hole of the reaming guide.